Runaway electron imaging spectrometry (REIS) system.

A portable Runaway Electron Imaging and Spectrometry System (REIS) was developed in ENEA-Frascati to measure synchrotron radiation spectra from in-flight runaway electrons in tokamaks. The REIS is a wide-angle optical system collecting simultaneously visible and infrared emission spectra using an incoherent bundle of fibers, in a spectral range that spans from 500 nm to 2500 nm, and visible images using a CCD color microcamera at a rate of 25 frames/s. The REIS system is supervised and managed using a dedicated LabVIEW program to acquire data simultaneously from three spectrometers every 20 ms (configurable down to 10 ms). An overview of the REIS architecture and acquisition system and resulting experimental data obtained in FTU are presented and discussed in this paper.

A fast multichannel Martin-Puplett interferometer for electron cyclotron emission measurements on JET.

A Martin Puplett interferometer for electron cyclotron emission (ECE) measurements from JET tokamak plasmas was extended to multichannel operation for simultaneous radial and oblique ECE measurements. This paper describes the new optics and the instrument's performance.

A key to improved ion core confinement in the JET tokamak: ion stiffness mitigation due to combined plasma rotation and low magnetic shear.

New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. [Phys. Rev. Lett. 102, 175002 (2009)] results from the combined effect of high rotational shear and low magnetic shear. The observations have important implications for the understanding of improved ion core confinement in advanced tokamak scenarios. Simulations using quasilinear fluid and gyrofluid models show features of stiffness mitigation, while nonlinear gyrokinetic simulations do not. The JET experiments indicate that advanced tokamak scenarios in future devices will require sufficient rotational shear and the capability of q profile manipulation.

Measure of electron cyclotron emission at multiple angles in high T(e) plasmas of JET.

The oblique electron cyclotron emission (ECE) diagnostic installed at JET allows simultaneous analysis of the ECE spectra along three lines of sight (with toroidal angles of 0°, ∼ 10°, and ∼ 20°) and two linear polarizations for each oblique line of sight. The diagnostic is capable of measuring EC emission over the band of 75­800 GHz with 5 ms time resolution and 7.5 GHz spectral resolution, and it is designed to investigate the features of ECE spectra related to electron distribution in the thermal velocity range. Instrumental accuracy was assessed using sources at different temperatures (77­900 K) and with plasma emission. ECE from high temperature plasmas and in the presence of fast ions has been compared to simulations performed with the modeling code SPECE, setting an upper limit to possible discrepancies from thermal emission.

Dynamics of tearing modes during strong electron cyclotron heating on the FTU tokamak.

The localized electron cyclotron resonance heating power that can suppress sawteeth reconnection often drives m = 2 tearing modes in a tokamak operating at constant current. The dynamics of mode onset and coupled mode evolution is described in detail and compared with a nonlinear theoretical model that identifies the effects of mode coupling, finite inertia of the rotating islands, and wall braking.

Tianeptine and alcohol dependence.

Several arguments are in favour of the use of antidepressant drugs in alcohol-dependent patients, especially those acting on the serotoninergic system: (1) neurochemical data indicate the interaction between alcohol and 5-HT metabolism, (2) pharmacological studies show an improvement in the behaviour of alcoholized animals treated with antidepressants, (3) depression is a frequent disease in alcoholic patients. Tianeptine has been shown to be active in the treatment of depression in patients with history of alcohol abuse or dependence. In a first double-blind study performed versus amitryptiline, depression after withdrawal was improved by tianeptine, and biological abnormalities usually related to chronic alcohol intake tended to decrease. Similar results were found in an open study carried out on 277 alcoholic patients treated for 1 year. As these patients were depressed, no definite conclusion could be drawn from these results in respect of a specific action of tianeptine on alcohol dependence. Thus, a multicentre double-blind study has been performed which compared tianeptine (12.5 mg t.i.d) and placebo in 342 non-depressed patients fulfilling DSM-III-R criteria for Psychoactive Substance Dependence (alcohol). Other inclusion criteria were: daily alcohol intake higher than 80 g, minimum score of 3 on the Short-Mast Questionnaire, mean corpuscular volume above 98 fl and/or gamma Gt more than twice the upper limit of normal. The patients were treated for 9 months. The intention-to-treat population and the per protocol population were made up of 327 patients and 111 patients, respectively. The main efficacy criterion was the absence of alcoholic relapse (abstinence) defined by the patient's statements, the investigators clinical judgement and some biological parameters: alcohol blood levels, gamma Gt levels. Secondary criteria were the evolution of the alcohol consumption in the patients who relapsed, cumulative abstinence duration, a visual analogue scale for the evaluation of the appetence for alcohol and the clinical global impressions scale. The statistical analysis showed no difference between both groups in respect of the maintenance of abstinence (intention-to-treat and per protocol populations). In spite of the methodological problems of the studies in dependence (choice of the inclusion and efficacy criteria, especially), the preliminary results obtained with the serotoninergic antidepressants were not confirmed in the different trials performed in the maintenance of alcohol abstinence. The indication of tianeptine should be restricted to the treatment of depressive syndromes, which have a high lifetime prevalence in the alcoholic patient, and which have a noticeable role on the alcoholic relapse.

Study of photoablation of rabbit corneas by Er:YAG laser.

BACKGROUND AND OBJECTIVE: This work studied the ablation mechanisms of rabbit corneas by the Erbium:YAG laser. The occurrence of thermal and mechanical damages in the tissue as a function of the laser fluence was also investigated. STUDY DESIGN/MATERIALS AND METHODS: The experiments were performed both on enucleated eyes and in vivo. An ultrafast imaging technique was used to investigate the dynamic evolution of the ablation. The treated samples underwent histological and ultrastructural study. RESULTS: A single high fluence laser shot led to the complete removal of the epithelium by a photomechanical effect. In eyes whose epithelium was manually removed, high fluence pulses resulted in evident tears in the stroma, whereas low fluence pulses led to few microns deep incisions, characterized by limited mechanical and thermal damages. CONCLUSION: The photomechanical action plays a significant role in the ablation of the cornea by Erbium laser. Precise control of the fluence is required to avoid cracking phenomena in the stroma.